No, not how large the universe is, but rather how much space different languages require, comparatively speaking.

I've just finished an advert in Polish, translated from English and it was a bit of a struggle to get it all to fit, keeping to the initial layout. Having some idea of how much more space is required would be great when it comes to discussing with the client. In the end they were very happy but I spent more time than should have been needed on the job.